Blow-nozzle for differential blasting of molten material



June 15, 1954 R. M. DOWNEY 7 2,681,255

BLOW-NOZZLE FOR DIFFERENTIAL BLASTING OF MOLTEN MATERIAL Filed Oct. 24, 1951 Patented June 15, 1954 BLOW-NOZZLE FOR ING OF MOL DIFFERENTIAL BLAST- TEN MATERIAL Richard M. Downey, North Judson, Ind., assignor to United States Gypsum Company, Chicago, 111., a corporation of Illinois Application October 24, 1951, Serial No. 252,854

3 Claims.

The present invention relates to the art of making fibers from molten material by means of a blast of gaseous fluid. It relates further to a blow-nozzle designed to accomplish this result.

The present invention is particularly concerned with the making of mineral wool fibers, glass fibers and the like, such as are used in various types of insulation, acoustic corrective material, etc.

Mineral wool, using the term generically as representative of all materials of that type, is usually made by blasting a stream of molten material of suitable composition by means of a blast of a gaseous fluid, such as compressed air,

have also been proposed.

It is one of the objects of the present invention to provide a method of first subdividing a falling stream of suitable molten material into relative smaller streams, which are then blasted into fibers by means of a stream of high velocity and high volume gaseous fluid, such as air or steam.

It is a further object to provide effective means, having no moving parts, which will provide two streams of such gas, at different volumes and velocities, so arranged as to first divide the molten material into smaller streams and then to cause a stream of high pressure gaseous fluid to hurl these small streams into space so as to further subdivide them and draw them out into fibers, which are then collected by the usual means and methods.

A further object of the present invention is to provide a blow-nozzle which will automatically produce two separate streams of gaseous fluid at difl'erent volumes and velocities, which are in predetermined relationship with each other, and whereby a single control will serve to modify the volumes and velocities without changing their relationship.

Other objects will become apparent from the further description and the hereunto appended claims considered in connection with the drawings in which Fig. 1 is a side elevation of the blow-nozzle of the present invention, also illustrating its method of use;

Fig. 2 is vertical section therethrough;

Fig. 3 is a front view thereof; and

Fig. 4 is a cross-section view along the line 4-4 of Fig. 2.

The method of producing the fibrous material internal threads 8 of so as merely to break up the stream into numerous individual smaller streams, which still continue to fall so that they will then be intercepted by a similar stream of gas, but of greater volume and velocity, so that the small streams will be thus blasted into fibers, which are then carried away to a point of collection by the blast. As the means of collection, and of producing the original stream of molten material, are outside of the scope of the present invention, they are not illustrated. The stream of molten material may hence be assumed to be coming from a suitable furnace, such as a cupola, and the fibers may be collected in a collection chamber having a perforated belt upon which the fibers form a felted web.

The blow-nozzle employed for carrying out this process consists of a shell 5, which may be cylindrical, if desired. If so, it may be provided at its rear end with an internally threaded opening 6 for the insertion of a suitable externally threaded supply pipe I for the gaseous fluid. At its forward end the shell is provided with internal threads 8. A closure is provided for the shell 5, being in the form of a deep externally threaded cap 9 which is screwed into the the body 5. This cap is provided with an internal cavity In which has internal threads H into which is screwed a plug [2 having an external flange l3 which, when the plug is screwed as far as it will go into the cavity ID, will abut against the inside wall of the cap or closure 9, thus forming a smaller chamber in the form of the cavity I0 within the cap 9. An aperture I 4 is formed in the plug I 2 so as to establish communication between the interior of the shell 5 and the cavity II]. There will thus be eventuated a larger space or chamber l5 within the shell 5.

The smaller, low-pressure chamber I ll communicates with a series or tier of small openings I 6 which are suitably arranged in the form of an arc centric with the center of the cap or closure 9. The are is a little more than a semicircle, i. e., greater than about 180 The larger, high-pressure, chamber I5 is in communication with a series or tier of somewhat larger openings ll. These are also preferably arranged in an are which is centric relative to the center of the cap 9, and may be concentric with the arc of the tier of smaller open- While but a single opening H is shown in the plug i2, it, will be obvious that this may be replaced by a number of openings, provided only that there be a division of the gaseous fluid, such as steam, between the larger high-pressure cham ber and the low-pressure chamber it].

Thus, when the gaseous fluid is admitted under its normal full pressure to the chamber through the supply pipe I, most of the fluid will be emitted. under substantially the same pressure from the tier of openings H at considerable velocity and volume. Some of the fiuid, however, will p us through the aperture Id into the low-pressure chamber it, where, by the throttling effect of said aperture, it will exert much less pressure, at which it will be discharged through the relatively smaller openings i=5, and at a lesser volume.

It will be evident that there will exist a fixed relationship between the pressures in the two chambers, this being determined by the size of the aperture l4. It will be equally obvious that as the amount of pressure in cham er i5 is increased, as by supplying gaseous fluid at a higher pressure, that this will automatically induce a higher pressure in chamber H), but the relationship between the pressures in these two chambers will remain the same. Therefore, but a single control valve will be needed to supply gaseous fluid to the nozzle. 7

When making ordinary mineral wool from me ted slag, glass or rock, a steam pressure of about to pounds per square inch is supplied to the nozzle through the supply pipe 7. With compressed air, somewhat higher pressures are indicated, say about 126 to pounds per square inch.

It is within contemplation of the inventor to make the two tiers of openings both in a straight line, or one of them in a curved line, or both curved, but for most, purposes an arrangement in which the two arcs are concentric and parts of true circles is most effective. One of the reasons for placing the holes in curved tiers is that the stream of molten material is usually substantially circular in cross section, and also that it has a tendency to wobble from side to side. With the blasts coming from arcuate tiers of openings there is a tendency to drive the molten stream into the center of the nozzle, so that it will be more evenly acted upon by all of the blow-openings in the nozzle. By first subdividing the stream 18 into smaller individual streams 19, the

subsequent further subdivision 20, and their attenuation into fibers 2 I, is greatly facilitated. As the entire apparatus is free from moving parts, it i simple to make, and easily controlled during the operation of making the mineral wool.

It will be self-evident that the nozzle constructed in accordance with .the present, invention may also be applied to the fiberization of other fluent materials, such as melted asphalt, wax etc, or be employed for the effective atomization of streams of liquid at other than fusion temperatures, such asthe spraying of oils into furnaces, or for coating various articles and materials, or for sprinkling extinguishing fluids upon confiagrations, etc.

The material of which the nozzle is constructed may be metallic or non-metallic, depending upo its intended use. Obvious modifications as t relative sizes, exact location of the supply pipei etc., are to be considered as within the intended scope of the present invention.

I claim:

1. A multiple jet difierential pressure blownozzle for blowing molten slag and the like into mineral wool, comprising a cylindrical internally threaded high-pressure gaseous fiuid chamber and a. closure therefor, the latter being internally threaded'and having a centrally therein positioned inwardly extending chamber closeable by an apertured plug screwed thereinto to thus form a second chamber in communication with the said high-pressure chamber through the apere ture in said plug, onearcuate row of relatively small blow-openings in said closure leading from the low-pressure chamber, and a second concentric larger arcuate row of larger blow-openings leading from said hi h-pressure chamber.

2. A blow-nozzle according to claim 1 in which the larger row of blow-openings is provided with larger openings near the center of the arc and smaller openings near the ends of the arcs.

3. A blow-nozzle according to claim 2 in which the largest openings are at the center of the arc and the openings are progressively smaller toward the ends or" the arc.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 328,226 Kennedy et al Oct. 13, 1885 1,809,787 McLaren June 9, 1931 2,076,445 Callander Apr, 6, 1937 2,136,158 Thomas Nov. 8, 1938 2,147,192 Carson Feb. 14, 1939 2,178,871 Drill Nov. 7, 1939 2,313,994 Grant Mar. 16, 1943 2,387,118 Callander Oct. 16', 1945 2,469,534 Wessels May 10, 1949 2,579,150 Leopold Dec. 18, 1951 

